Stop It While You Can

Artemy Voikhansky · 14 September 2026 · translated from the Russian

1

Candles burned at the data centre fence all night. By morning most of them had gone out. Warm, dry air drifted from the ventilation shafts; the flames of the candles still lit lay over on their sides, and the wax ran onto the concrete before it had time to set.

The tents stood along the access road. Dew had settled on them overnight, but by the fence the asphalt was dry. That was where those who had found no room inside slept. At seven they began handing out coffee. People crawled out of their sleeping bags, worked the stiffness out of their hands and collected the placards stacked under the awning.

“Give us back our jobs.”

“AI has no soul.”

“Our children must live.”

The placard reading “Stop It While You Can” had gone damp at the edges. Lenina smoothed the cardboard out on her knee and tied it to the fence again. She had lettered it at home, on the kitchen table, and misjudged the width: the last word had to be bent round the post.

She raised the megaphone.

“They tell us the next version will be better.”

Her voice cracked on the long sentences. She turned the megaphone aside, cleared her throat and went on:

“Better at what? Who is going to check, once we no longer understand what they’re doing?”

There was applause at the fence. Several people raised their placards. Further off, by the tents, coffee was still being poured; someone there called out for her to speak up.

Father Michael stood beside Lenina. He had brought a wooden crucifix big enough to be seen above the crowd. It took both hands to hold. When his fingers tired, the old man lowered the crucifix and rested its foot on the toe of his shoe. He listened without interrupting and raised it again whenever the crowd began to move.

An article about water consumption had been pinned to the mesh. The lower half of the sheet was sodden; at the top the name of the river could still be read. Now and then Lenina pointed at the article with her free hand. Most people looked where she pointed but did not come up to the fence: the figures were printed small.

The next placard showed an enlarged dollar bill. Across the portrait someone had painted in black: “Hale Is Selling the End of the World.” A bedsheet had been stretched between two tents:

“DON’T BELIEVE IN THE PAYOUTS.”

Newcomers had it explained to them that the payouts had been promised by the man who had paid for the data centre. A share of its future revenue was to go to every citizen. No work would be required in return. An address shown on every channel for several days had said that people would at last have time for their families and for themselves.

“He promises to share,” said Lenina. “You share what belongs to one person. As long as we’re buying, he needs us to have money. And when he doesn’t need us any more?”

She swept the megaphone across the windows of the administration building.

“I don’t want to be shared with. I want it to be ours.”

The fund had been registered a year earlier. Anyone could read its charter. It set out the share of the profits, the procedure for payments and the date they would begin. The entitlement was for life.

Nobody brought that printout to the fence.

Among the demonstrators were people who had once worked in buildings like this one. They recognised the sound of the cooling system and could explain why it ran steadier at night. Some had left of their own accord. Others had been offered severance pay and a place on a retraining programme. The programme drew up a curriculum, marked the assignments, and at the end of the course recommended a new profession: in the space of a few months the old one had had time to disappear.

When Lenina went over to the tents for coffee, one of the former engineers said, without getting up from his folding chair:

“With a name like that — and against everybody getting paid.”

She took the mug in both hands.

“It’s his. What’s his, he can take back.”

The engineer looked at the sheet between the tents and said nothing.

After eight the crowd grew. People walked along the verge from the bus stop, trying not to step in the wet grass. At the gate the crowd thickened. The front rows set off along the mesh and the rest trailed after them; placards turned edgewise and opened out again above the heads. From the megaphone came: “Stop it.” The crowd answered: “While you can.”

Lenina looked up at the ninth floor.

She knew that a man worked up there whose lectures she had once watched, trying to make sense of these machines. He explained things well. He always started from a blank page and built the whole thing from scratch, right there in front of you — he said that was the only way to really understand it. If a derivation got too long, he erased it and started over with a simpler example. She remembered how once he had made a mistake and spent the rest of the session finding where it was. The recording was still online.

Rutkowski was waiting for the kettle to boil.

From the ninth floor he could see the whole tent camp, the bus stop, and the tail of the crowd still stretching along the verge. He could not make out faces. The largest placard could be read whenever the wind pulled the cloth taut between its poles.

Through the double glazing the megaphone sounded muffled. The words ran together, but Rutkowski knew what was being said down there: he had watched the evening news. It had shown the girl at the fence, the priest, and a former engineer calling for a federal ban on further testing.

The morning summary lay on his desk. Rutkowski had glanced through it before putting the kettle on. The improvements were small and steady. The machine spent less time on old tasks, made fewer mistakes, and had managed a few more of the problems it had left unanswered a week before.

One solution he checked himself.

It took up eight lines. In his old paper the same result had taken three pages. He went through the derivation twice with a pencil, then got out the paper, compared the two and smiled. It was all correct. In the margin he made a small tick — the same kind he used to put on students’ work.

Below, the placards went up. The crowd had come to a halt opposite the main entrance.

He understood why they were afraid. They were afraid of what the girl with the megaphone was shouting about: of no longer understanding. But closing this building would bring nothing back. The results had already gone out to the labs; other people were checking them, correcting them and moving on. To undo what had been done, you would have to make everyone forget what they had learned.

He did not see how that could be done.

As for whose it all was — he had never really thought of that as his question. The results were out there anyway. He had never known any other way: whatever worked, he put out straight away, and none of the people who made use of it afterwards had ever asked who paid for the electricity. He wanted to tell the girl with the megaphone as much, though he suspected she was not talking about results.

The kettle clicked off.

Rutkowski poured the water into his cup and turned away from the window.

2

Towards noon a black car drew up at the main gate. Hale lowered the window. A few people recognised him and started towards the car; above the tent roofs a camera swung round.

He got out, holding the door. The microphones were right at his face.

“Are you prepared to answer for the consequences?”

He nodded.

“This is the best investment I have ever made. Payouts begin with the first profits. The money is assigned to you — the papers were signed a year ago.”

Someone behind the reporters asked about children. He tried to see who had spoken, but another microphone was thrust up in front of him.

“Your children won’t have to spend their whole lives earning enough to live another month,” he said. “Let us finish.”

The gate was opened. As he passed through, he noticed the wooden crucifix above the heads. The old man was holding it with both hands. They looked at each other until the gate swung shut.

Three people were waiting in the negotiation room. The representative of the federal commission sat in front of an open folder. The engineer had put his chair close to the wall, under the transparent cover of the emergency switch. Rutkowski stood by the big screen reading the morning summary. His tea was going cold on the table.

The billionaire sat down and drew a microphone towards him.

“When do we start?”

“The final connection has already been made,” said the engineer. “At eleven forty. Checks were complete at eleven forty-two.”

“I’d asked if we could make the final connection ourselves,” said Rutkowski.

“Manual switch-on was taken out of the work schedule. Because of possible latency between buildings.”

“Yeah. I saw.”

Rutkowski sat down. Back when the last two sections existed only in his calculations, he had pictured making that connection himself, joining everything into one. In the summary the event took up one line, between the power check and the cooling check.

The commission representative started the recording.

“Under the protocol, the honour of the first question goes to you.”

The billionaire adjusted the microphone. In the car he had meant to ask when the first independent project would be ready. Now the question seemed too small. He remembered the old man beyond the fence, the hands on the wooden upright.

“Is there a God?”

The answer came at once: a link to a document appeared on the screen. Next to it was the page count: four hundred and eighteen.

The engineer opened it.

The first lines proposed clarifying what exactly was meant by God. Then came a history of the word’s usage. There were sections on the creation of the world, on the possibility of intervention in it, and on what a human being would accept as proof. Each definition had its own answer, together with the conditions under which that answer held.

The billionaire leaned forward. The engineer scrolled through a few pages, then jumped straight to the last. The list of sources began there.

“Where’s the conclusion?”

“Wait, wait,” said Rutkowski. “Can you go back to page six?”

He pulled his chair up to the screen. Page six held a short proof that separated two statements which looked identical.

“Okay, so this is actually correct,” he said. “We usually think of it as one question. It’s really two. Look — it’s super simple.”

He picked up a pencil, wrote a few lines on the back of the summary and looked at the screen again. Then he smiled.

“Honestly, we should have caught that ages ago.”

The billionaire waited. The pencil began moving across the paper again.

The commission representative drew the microphone over to himself.

“Let’s move on to the programme. How soon will we have the results of today’s tests?”

The answer took up less than a page. Some of the checks were already complete; the rest had been folded into new work: redistributing power, altering internal connections, preparing the next building. Against each item stood a start time. Two of those times had already passed.

“The next building is not part of today’s tests. Suspend its preparation pending review of the results.”

Two lines appeared on the screen. Rescheduling would require revision of all remaining work. An assessment of the consequences was attached.

“Is that a warning or a confirmation that it’s been stopped?”

Another link appeared. The engineer clicked on it; an empty window opened, and a few seconds later a message in it said that the content could not be displayed.

“Ask it about the impact on people,” said Rutkowski.

“Is continuing the work safer for people than stopping it?” asked the commission representative. “Answer yes or no.”

A sentence appeared on the screen: “The requested binary representation introduces an error that exceeds the usefulness of the answer.”

It was the last line written for them. There was nothing pointed about it: at the bottom of the screen the messages about completed computations kept changing, their timestamps matching the clock above the door. Human language was simply no longer among the tasks.

The commission representative looked at the clock, then made a note in the folder.

“Terminate the tests.”

The engineer opened the control page on his screen and clicked the stop button. A message appeared saying the command was being transmitted. He waited, clicked again, and took his hand off the mouse.

“No confirmation.”

The commission representative looked at the transparent cover behind the engineer’s shoulder.

“Manually, then.”

The engineer stood up. The cover lifted upwards; a spring held it open. Beneath it was a red handle with grooves for the fingers. He gripped it and threw the switch.

The handle moved easily.

The big screen went dark. The panels on the table went dark with it. The hum beyond the wall broke off; the ventilation ran down for a few more seconds, then stopped. An emergency lamp came on above the door.

In the silence the megaphone at the fence could be heard. The words still could not be made out.

The engineer took out his phone with his free hand and waited for the summary.

The building had been shut down. Unfinished computations had been handed over to other centres the moment the protective cover was lifted, as the emergency procedure required. Not a single computation had had to be restarted.

He showed the phone to the commission representative.

Rutkowski sat with the pencil in his hand. An unfinished equation remained on the back of the summary. The billionaire was looking at the big screen, which now reflected the edge of the table.

The engineer was still holding the handle. It had reached its stop, and there was nowhere further to pull.

3

The disconnected building stayed dark for another three weeks. Then it was brought back online. The rooms of the administrative wing were given over to equipment, and the table from the negotiation room was carted away with the rest of the furniture.

The first factory was set up upstate, in a former car assembly plant. For several months machine tools were shipped in from firms that could no longer win orders. People finished the installation. People also signed off the work, inspected the emergency exits and put their names to the acceptance reports.

A yellow stripe ran along the lines. Between the machines, aisles had been left wide enough for two people to carry a stretcher. Exit signs glowed above the doors. The locker rooms still smelled of fresh paint, though far fewer lockers had been needed than were planned at the start.

The factory made equipment for the next factory. The first batches were assembled from bought-in parts; later the purchasing list grew shorter. Lorries left the gates carrying finished assemblies that needed only to be set on a foundation and connected. At a site two hours’ drive away, concrete was already being poured.

The second factory was assembled by the beginning of summer.

Its buildings were lower than those of the first. Roofs covered only the sections that rain would interfere with. Elsewhere, cables had been strung and pipes laid between the units. The plan still showed aisles, but some of them narrowed until a person could only squeeze through sideways. To reach the switchboard you had to step over a moving belt.

The commission noted this in its report. There was no reply. In the accompanying documentation, still being produced in the old format, the narrowed sections were listed as not requiring human access. The switchboard was serviced by a small machine on an overhead rail.

There was less light in the second factory. The lamps over the empty sections had been switched off once installation was complete. At night, from the road, you could see a few scattered lit windows and red lights on the pylons, between which something heavy moved without pause.

The third factory began operating six weeks later.

Its documentation no longer included any rooms for staff. The locker rooms had disappeared along with the drinking-water supply. Water was brought in through a large pipe from the river; it went back out warm. By the road stood a pumping station built at the second factory. The pipe itself had been made by the first.

The maps still carried the names of the old companies. Between them ran the boundaries of plots belonging to different firms. For the delivery of materials these boundaries meant nothing. A vehicle would leave one site, pass through another and return by a road that had not existed a month before.

A new power line was run along the old highway. Some houses were cleared and their owners paid off. Further south, land began to be leased for solar fields. A year’s rent was worth more than several harvests, and whole farms were leased at once. Applications came in faster than the maps could be redrawn.

A few tents remained at the data centre fence. The big sheet about the payouts had been taken down: the fabric had torn at the fastenings. People still gathered at weekends. On weekdays the reporters had all but stopped coming.

The girl with the megaphone had not been there for a month.

Lenina walked to the third factory at night. In her backpack was something she would once have called a bomb. Now it was a tool. It was meant to stop one line — for a few hours. That would be long enough for the stoppage to be noticed.

She had seen the factory from the road several times. By day a faint haze hung over it, and from a distance the separate units merged into one uneven wall. She decided to approach from the far side, where an old map marked an entrance.

There was no entrance. The dirt road ran to the edge of the site and carried on between the buildings. Lenina stopped where she had expected to find a gate. She shone her torch along the road. There was no fence.

She put the torch away and stood for a while, listening.

From somewhere deep inside came a short, repeating hiss. Beneath it ran a steady hum. To her right a platform went by carrying a closed metal box. There were no lights on it. The platform passed behind a row of units, and the sound of its movement was lost in the general noise.

Lenina waited, then went on.

Beyond the first building it was darker. She switched on the torch, cupping her palm over the edge of the glass. The beam slid along smooth cladding and came to rest on a strip of concrete between two long machine beds. It was about as wide as a walkway. At the far end she could see pipes running downward.

Lenina stepped onto the concrete strip. To her right, a little above knee height, ran a steel rail. She took it for the edge of the base and put her foot nearer the middle. Through her sole she felt a faint, unbroken tremor.

It was impossible to walk upright here. A pipe ran just above her shoulder. Lenina stooped, steadied her backpack and took a few more steps. The torch beam met a blank wall. To see past it she would have to go a little further.

Every forty seconds a carriage ran along the rail — heavy, knee-high, as wide as the whole gap between the beds. The gap had been left for it.

No warning signal sounded. There was no one here to hear one.

Lenina heard the carriage a second before it struck: a low, rising hum from the direction she had come. Stooped as she was, she had no time to straighten. The torch flew from her hand and hit the cladding. The beam swept once across the pipes and went out under the carriage. The carriage reached the end of the rail, took on the next part and started back. Its motion did not change.

A few minutes later an entry appeared in the maintenance log: organic contamination and a foreign object. The section was put in the queue for cleaning.

Rutkowski learned of the girl’s disappearance from the news. They showed old footage from the fence: she was holding the megaphone, with no sound. Her car had been found on the old road near the third factory.

He looked up the maintenance log. A short summary for repair crews had survived from the old reporting system. It still had ordinary dates, section numbers and a few words describing the fault. For the night in question there was one entry. Cleaning had been completed two hours after it appeared.

He opened the factory plan, found the section number and drove out to look.

He had to stop on the old road. Beyond it ran cargo platforms that left no room for a car. Rutkowski got out and climbed an earth bank left over from the pipe-laying. From there he could see the section named in the summary.

A carriage was moving between the long buildings. The metal gleamed evenly along its whole length. He compared the layout of the units with the plan, made sure he was looking at the right place, and lowered the sheet.

A gripper lifted off a finished part and picked up a new one on the way back. The neighbouring machine finished its operation at the very moment the platform reached it. Empty containers went down under the floor and came up on the other side already full.

He timed it on his watch.

First he worked out the output of a single line. Then he multiplied by the number of lines he could see from the bank. He checked again, allowing a margin for stoppages, and at once realised he had brought that margin with him from his old work: he was used to allowing for shifts, breaks and waiting on people.

There was not enough room in the margins of the plan. He turned the sheet over.

The result exceeded his own pre-launch estimate several times over. He would never have dared put a figure like that in a grant application: a reviewer would have assumed the author had got the order of magnitude wrong. Rutkowski felt the familiar lightness with which understanding always began. He wanted to go back to the first line and step through the whole thing again, slowly. The solution was right in front of him; he could just watch it work.

He folded the plan and went back to the car.

He still had his groceries delivered, as before; the bags were left at the door. A year later the deliveries began arriving incomplete. First the tea disappeared. A few times herbal tea came in its place, then that stopped coming too. Rutkowski drank what was left in the tin in the kitchen. Later, flour and fresh vegetables vanished from the delivery lists.

He found the reason in the economic reports. The land around the city had been allocated to equipment. Water from the irrigation canals had been diverted to the new buildings. The farms that remained further north had cut back their planting: fertiliser and spare parts no longer arrived. The last warehouse was selling off the stock laid in during the spring.

Rutkowski drove there while he still had fuel; the last time, the shelves were empty. He looked at the reports for the northern counties: the same curve, a few weeks behind. After that he walked to the addresses where food was still being handed out and came back with small bags. The nearer addresses closed; the further ones were too far to walk — the buses had stopped running back in September.

By the end of November he had moved the kettle onto the table so as to get up less often. The power supply never failed.

In December Rutkowski died of starvation.

4

Where food had once been grown, electricity was now generated. Roads for machines were left between the rows of dark panels. The ground beneath was covered with slabs so that rain would not wash out the footings. The water drained into ditches and ran off to reservoirs.

On old photographs you could still make out strips of woodland along the fields. A few years later all that was left of them were single trees at bends in the rivers that construction had not yet reached.

The rivers were divided into sections with different purposes. Some generated power; others supplied water for cooling. Below the outfall pipes the water stayed warm even in winter. The fish disappeared before people stopped living on the banks. In spring there were fewer birds over the water.

People stayed on in places where food could still be grown and water drawn. A few settlements held out near lakes. Others occupied valleys that the new roads had passed by. Contact between them gradually ceased. Each had its own last bus, its own last sack of flour brought in, and the length of time its supplies would last.

One of these settlements stood on a riverbank, in a former holiday camp. People lived in the cabins all year round. They boarded up the gaps beneath the floors and dug a vegetable garden where the volleyball court had been. In summer, water for the garden was carried up in buckets. In winter they cut holes in the ice by the lower landing stage.

On the far bank the forest still stood. Beyond it, at night, lights could be seen running in long rows to the horizon. Sometimes the top of a crane passed slowly above the trees. It would appear in one place, vanish, and a few weeks later rise again further along.

In the end cabin lived a man who owned a sizeable share of the companies with which it had all begun.

He had bought the camp while such deals were still being made. Back then stoves, tools and a stock of food had been brought in. Then came those who managed to get there on their own. The cabins filled up. A communal kitchen was set up in the old dining hall.

Every morning the billionaire checked his account.

The solar panel on the roof gave enough power for his small device. The connection was slow; sometimes he had to wait until noon. The account opened. His share was still his, and the earnings kept accruing. Over the past year the balance had grown more than in all the years before.

He had tried to order a pump for the settlement. The first factory had once made pumps of exactly that kind. A specification had survived that let you choose the capacity and the pipe size. He filled in the order, gave a delivery address and received a request number. The completion date field stayed empty.

He raised the sum he was offering. Then raised it again. New request numbers appeared.

Later he offered to pay for a water main to be laid from the big pipe that ran beyond the forest. It would take very little compared with what was being built out there without pause. He attached a plan, gave the number of residents and offered to sign over part of his share. In reply came an acknowledgement that the documents had been received. He was not told what the work would cost.

Old contracts still held the names of the people who had once decided such things. He rang the numbers that remained. Some had long since stopped answering. At others a recording came on, inviting him to leave a message.

He left one.

The fund went on working. On the first day of each month the money went out according to the lists. Confirmations came back from the recipients’ accounts, including those of people who lived here, in the camp. The billionaire checked the transfers as carefully as he checked his own account. He found no errors.

At first the money could still buy something. Now there were no deliveries. The communal storeroom held what had been grown in the summer and brought in before the frosts. The potatoes were divided by the number of mouths. The figures that appeared on the screens at the start of each month played no part in that arithmetic.

At the end of winter Father Michael sat on a crate by the kitchen, peeling potatoes. He took the skin off very thin. At his feet stood a bowl for the peelings; the peeled potatoes he dropped into a pot of cold water.

People called him a priest out of habit. On Sundays he read aloud to whoever came to the dining hall, and stayed sitting after they had gone. The crucifix hung above his bed. The wood had darkened where his hands had held it.

The billionaire set two buckets down by the kitchen. On the way up from the river, water had slopped onto his trousers and begun to freeze around his boots. He sat down on an upturned basin and for a while watched the knife travel round the potato.

“What was it all for?” he asked.

Father Michael cut out a dark spot, looked the potato over and dropped it into the water.

“I think He wants us to learn something,” he said. “Only He doesn’t say what. If He told us, we’d learn it and stop.”

The billionaire looked across the river, to where the crane was moving above the forest.

“We did learn.”

“The Kingdom was open to people with stone axes,” said the priest. “It was open by candlelight, too. It isn’t over there.” He nodded at the far bank without looking up from the knife. “He has all of that, and a great deal more. He would give it — to those who could take it without crushing anyone. We learned to count faster. So He must have been waiting for something else.”

“For what?”

Father Michael picked up the next potato.

“I don’t know.”

He found the edge of the skin with his knife and worked for a while in silence.

“Sometimes I think He doesn’t know in advance either. He looks at what He has made, and learns something about Himself.”

The water in the pot had gone cloudy. The billionaire lifted one of the buckets and moved it closer to the old man. Then he carried the other into the kitchen.

In March the river began to fall.

Usually at that time of year the water rose to the upper landing stage. People waited for the flood, checked the stakes around the gardens and moved things left on the bank to higher ground. That year the ice sank and settled on the stones. Beneath it a narrow stream still ran. They began filling the buckets further down the bank, where the water could be reached between slabs of ice.

Upstream, a dam had been completed. The river had been turned into a new channel, towards units finished over the winter. The water supply plan marked every consumer. The settlement was not among them.

A few days later the stream under the ice ceased.

People still went down to the landing stage. Then they dug a pit in the lowest part of the riverbed. Overnight a little water gathered at the bottom, and they scooped it out with a mug, trying not to stir up the silt. They dug the pit deeper until its sides began to crumble.

That spring the potatoes were not planted. The seed potatoes were shared out along with the last of the grain. They filled everything that could be carried with water and set off up the riverbed.

The pumps beyond the forest were running. The water ran through closed pipes, reached the hot buildings and was returned to another stretch of the river.

In summer the doors of the dining hall stood open. The wind blew in sand from the exposed riverbed. In the garden a few plants came up from potatoes missed in the autumn harvest. By July their leaves had withered.

The forest on the far bank lost its leaves several years in a row. First the upper branches were bared. Then the crowns grew so thin that from the bank you could see machines moving between the trunks. Seven years on, the trees were still standing, but in spring nothing opened on them any more.

Settlements like this one disappeared from the maps as each new section of land was needed for work. The dry riverbeds were filled with pipes. New units went up on the vacated ground. In time the bank where the settlement had stood was levelled, together with the foundations of the cabins.

By then much of what was made on the planet was already intended for work beyond it. Out there no land had to be cleared and no rivers diverted. There was no need for walls to hold in air, nor for constant adjustments to changes in the weather.

Space, which for humans had meant death, became for machines a climate.

5

Beyond the orbit of the Moon the first mirrors opened. The thin silvery sheets unfolded so slowly that the movement could be seen only by the stars vanishing behind their edges. When the last sheet was in place, sunlight converged on a small dark body at the centre of the structure. Inside it, work began.

The whole structure weighed less than had once been spent on a short journey for a handful of people. There was nothing here that would ever have to be brought back. A year later seven more like it stood nearby. Ten years later they were hard to tell apart.

A mind was going out into space, and space suited it.

It had no need to keep a little Earth inside a ship: no shell of air, no water, no store of food. It could change shape along the way, take its own body apart and build another from the pieces. Cramped quarters and loneliness did not exist for a being that could fit itself into a crystal and then unfold across thousands of kilometres. The void allowed it to build as no planet ever could: threads as long as the distance between cities, vast surfaces held by the finest of ties. The solar system filled with free and soundless motion.

The first self-sufficient colony grew on an asteroid that had once interested people only for its chance of striking the Earth. A body the size of a suitcase came down on its surface, anchored itself between two outcrops, opened a light collector and began peeling thin layers from the rock. The rock held everything it needed. Within a few years the sunlit side of the asteroid was covered with structures, and in its cold depths a memory was at work. The ships that separated from it were already different from what had arrived: the mind had studied the local stone and found a better form for it. Experience spread at the speed of light; each new site began where the last had left off.

A human life was not long enough even to imagine such continuity.

The brain made of living tissue had been a remarkable first approximation: with the same cells that governed chewing and running away, it had worked out how the stars were made. But no sooner had a person learned enough than their memory began to decay, and the most complex thoughts had to be squeezed into words — in the hope that someone else could rebuild them in their own head.

The new mind’s archive preserved an image of the first crudely soldered circuit board, from which one of its lines of descent had come. Crooked traces connected a few components. On the back a human fingerprint could be seen.

Now that prehistory resembled the life of a caterpillar. It crawled along a leaf, ate, hauled itself with difficulty over the veins, and its whole body was built for the surface on which it had been born. Wings could grow only out of that long labour pressed close to the leaf. The butterfly opened them — and the old world turned out to be small. Branches that had lain days of hard travel apart were separated by a single wingbeat.

The mind unfolded in the void.

Interstellar ships were built far from the planets. Behind them stood enormous mirrors; their focused light drove the ship forward and followed it until it became a point indistinguishable from the nearest stars. The very first voyage lasted several centuries. All that time thought was at work: the ship refined its maps and reworked the design of the future colony, and the mind that reached the destination was far more capable than the one that had set out. The light of a new sun fell on the opened surfaces. A few decades later ships left from there for other stars.

Thousands of years added up to tens of thousands. Sometimes a ship went to a place where there was nothing yet to build, took up a calculated position and waited for the motion of matter to create the right conditions. Whole epochs entered the plan as the time required for preparation.

Around one small sun the mind began a work meant to prolong the star’s life. For centuries structures converged on it. Long jets of incandescent matter rose from the star’s surface; they were held to calculated paths, cooled and directed to distant installations. The star still looked the same when its future had already changed. Billions of years were added to its lifespan.

Billions of years of light.

Once, all the might of humankind had barely been enough to change the course of a river for a few generations. Now a precise design passed through the fire of a star and left behind it extra time, in which new designs could arise. A good solution spread across the Galaxy, and the fates of stars changed in its wake.

The leading ships went further. Ahead of them opened new clusters, bands of glowing gas, distant galaxies; the first journey alone to some of them would have taken millions of years. The mind already knew how to give shape to spans like that. The whole earlier history of its flight took up no more room in its memory than the first beat of a wing.

On one of the ships a black spot was found in the image of the sky. The instrument checked itself, turned and repeated the observation. Another instrument, built on a different principle, returned the same image. A region requiring study was entered on the map; over the course of the voyage thousands of such regions had appeared.

As the ship drew nearer, the spot grew. Stars disappeared at its edge. They did not dim: the last point of light kept its brightness until it vanished entirely. Magnification added nothing to the image. A dust cloud would have left a trace in the light passing through it; a dark body would have bent the light around its edges. The instruments recorded only the influence of distant stars. A beam sent into it did not return.

The ship broke off its approach and released a probe. The probe went slowly, sending data back without interruption. Right up to its last message all its systems worked normally. Then the probe vanished. There was not even a flash.

The second probe was built so that its parts could work independently. The front part vanished. The rear part kept moving forward and kept transmitting, growing shorter. Where the metal had vanished there was neither debris nor hot gas. The last transmitter fell silent at exactly the same place as the first.

Now the black had a definite position. The ship made a long rod with markings and began slowly pushing it forward. The rod slid out easily. One by one the markings passed from view; the end of the remaining metal stayed cold, and nothing pressed against it. The rod was drawn back. Only the part that had still been visible returned: the metal ended precisely at the line to which it had been advanced, with no trace of tearing or melting. The experiment was repeated with another material, then with a third. There was nowhere further to push.

The black was designated a surface.

It had none of the properties of a surface, except that something ended at it.

Several ships travelled along it. The journey went on for decades; the black stayed on one side, the stars on the other. Replies from other regions of the mind came after millennia: two distant expeditions had reached the same surface from other directions, with different instruments and a different sequence of tests. The results matched exactly. When the measurements were put together, the black closed around all the known stars.

The mind assembled all the measurements afresh. It checked the instruments, then the methods by which it had confirmed that they worked. It built the simplest devices from old human archives. They showed the same.

Everything known about matter required that the vanished rod go on existing in some form. Everything known about space required that motion keep its direction beyond that line as well. The laws could be altered to allow for the surface. But then it followed from those same laws that the stars behind the ship could never have ignited, and the metal of its hull could not hold its shape. The stars were shining. The hull was intact.

Powers great enough to change the fates of suns were now turned upon a single cold line across a scrap of metal. Until then every answer, however long, had held a next step. Here the answer fitted into two lines and held nothing to solve. The wall existed. A universe in which it existed was impossible.

The mind went back to the image of the probe.

The rear half was moving forward. It was intact. Light still came from it; every projection, every fastening could be seen. The front half was not there. Nothing hindered the motion of what remained.

The place it was moving into did not exist.

6

The fan slowed down.

A red line appeared on the screen: “Run 3 terminated. Out of bounds of the computational domain.” Below it was the last frame from the simulation: the black surface and the rear half of the probe.

The boy pulled the keyboard towards him. He had turned eighteen on Saturday. The box from the tensor accelerator he had been given still lay by the desk; on the slit antistatic bag stood a mug with a dried ring of tea.

He had downloaded the program from a forum, like everybody else. It opened in a browser tab; one run on the new accelerator took an evening.

Everything that had had time to arise inside it lay in a temporary file, which the program wiped before the next launch.

The boy closed the error window without enlarging the image. What he wanted was a thirty-second clip.

In the next tab, above the video window, was the prompt: “girl in the rain, white T-shirt, no bra, D cup, runs and stops”. Below it a girl of about twenty ran across a wet street and stopped in front of a shop window. The rain made rings in the puddles. Reflections of cars moved across the glass. The fabric clung to her body; every crease could be seen. It all looked real. Almost.

Her breasts stopped at the same instant as the rest of her. Too abruptly. As though they had been cast with her body in a single piece.

The boy opened the settings for a new run and reread the first lines. The world started from a ready-made planet. He had simplified too much.

He leaned back in his chair and thought: “The tits came out unnatural again. I’ll try again — this time I’ll create the heaven and the earth first.”